The present invention relates to a device for applying surface pressure to a moving workpiece, for example wooden plate or the like, to which surface pressure, for example for connecting thereto of a sheet of foil, is applied by means of endless pressing belts, the operating strands of which press against the outer surfaces of the workpiece being treated.
In conventional surface pressure applying devices of the foregoing type the pressing belts are pressed against the surfaces of the workpiece by means of pressure medium admitted into pressure chambers provided in the device; these pressure chambers are normally each enclosed by the operating strand of the pressing belt, a rectangular pressure plate and a sealing supported against the pressing belt and provided on the peripheral edge of the pressure plate.
The device of the type under discussion is disclosed in EP No. 0,026,396. The straight-line sealing strips extending over the longitudinal and transversal edges of the pressure plate form one sealing, and a rectangular seal forms a sealing on the pressure plate.
If a lubrication agent is to be supplied to each pressing belt and to those sealing strips which form a seal in the transversal direction of the device, are intensively supplied with the lubrication agent whereas the lubrication of the seal in the region of the outlet of the pressing belt is insufficient. The straight-line sealing strips forming the seal in the longitudinal direction contain the lubrication agent only in the region of the inlet of the pressing belt while their remaining portions can dry out.